WESTFORD, Mass. (AP), Aug 31 - His helmeted head violently shook and banged against the padded rollbar, making it difficult for Ken Makuch to see where across a barren and windswept landscape he was driving.

Which was straight ahead... extremely fast... into the record book.

On Aug. 12, during Speed Week on the storied Bonneville Salt Flats in Utah, Makuch set an XF/GR classification record of 161.081 mph driving the Ford flathead roadster he built in his auto-repair garage in Westford.

The previous record in the classification was 153.603 mph.

The flathead V-8 engine was built by Ford from 1932 to 1953, automotive ingenuity valued famously by Clyde Barrow for providing dependable stolen getaways with Bonnie Parker. (The outlaw even wrote a letter to Henry Ford in April 1934 complimenting him for his product.) Today, flatheads are rebuilt into roadsters chasing land-speed records that warm the hearts of the engine's cultist devotees.

``You got to have an engine that can make the horsepower,'' says Makuch, who can build that. ``But then you got to have somebody crazy enough to hold it to the floor.''

That crazy somebody is also Makuch, he acknowledges with a smile.

The salt flat was swept by crosswinds from one direction, and then the other, as Makuch drove along a straight seven-mile course for 2 1/2 minutes. Settling deep inside his 1929 roadster, wearing a safety suit and full-face helmet, with a small piece of metal as his windscreen, the 49-year-old father of three held it to the floor.

``You have two miles to go as fast as you can, then you hold your speed for one mile,'' Makuch says. ``That's kind of how it works.''

The 161.081 record was an average speed over two gasoline-powered runs on successive days. Makuch estimates he approached 185 mph when running on nitrous fuel and setting a speed record in that fuel category that was voided by incorrect paperwork on his part.

This was his third trip in five years to Speed Week at Bonneville. With a larger car in the same XF/GR classification, Makuch registered 138 mph four years ago. After modifying the engine, he did 148 mph two years ago.

The engine that evolved into a record-setter was a 12-year process, Makuch says.

He speaks of Bonneville as if this hot and desolate place of fast cars and dehydration is the holy land. Just standing in the pit area 100 or so yards from a course on which a vehicle might zoom past at 375 mph ``is exhilarating,'' Makuch says.

``You see the car. And the sound is behind the car.''

While having no desire to go to Bonneville ("hot, noisy, smelly''), Makuch's wife, Susan, has come to appreciate her husband's skill at building engines. She sees congratulatory postings on the Internet from flathead roadster fans.

Speed can be bought in many racing classifications, says Susan Makuch, but ``the flathead requires skill because there is no machine to do what (Ken has) done. It all has to be done by hand. He combined a number of different theories to make it do what it did.''

As Makuch explains, he cannot just send a large check to some Jack Roush requesting a 1,000-horsepower small-block Chevy. He relies on a network of devotees, including his fellow members in the Ty-Rods Car Club, and frequent FedEx deliveries. He confers with an expert in California, Jimmy Stevens, whom Makuch considers a flathead genius. The rollbar chassis was engineered and built by David Beard of Merrimack N.H., assisted by Makuch's son, Matthew, 19, as his Westford Academy senior internship.

The engineering done, the parts built, the car needed to be assembled to precise specifications to gain approval for racing at Bonneville. Makuch did that over 35 days between doing work for customers at his Superior Auto Repair on Groton Road. He worked 12-14 hours a day. He was still rushing to put the decals on the car the night before loading it into a trailer and heading for Bonneville.

Matthew Makuch, headed to UMass Lowell to study mechanical engineering, and his brother Dan, 17, heading into his senior year at Westford Academy, accompanied their father on his Bonneville adventure.

The roadster turned out fine. During the four-day, 2,500-mile drive to Utah, though, the No. 6 injector began failing on the 2004 Silverado diesel pickup hauling the trailer carrying the roadster. (Eventually, a new engine needed to be installed by a Chevrolet dealership for the ride home.)

``A lot of people go to Bonneville for 20 years and never get close (to a record),'' Makuch says. ``It generally doesn't happen when you have a brand-new built car. Usually, there is an issue that needs tuning and adjusting.''

Makuch moved to Massachusetts in 1984 and worked as a Mercedes-Benz mechanic, and on a Can-Am and Sports Car Club of America race crew. He was later a chief mechanic for Honda's SCCA race team.

On the drive home from Bonneville, Makuch stopped in Emlenton, Pa., to visit his 84-year-old mother, Anna, who was ``tickled that her boy did something smart,'' says Makuch, laughing.

Soon after arriving back in Westford, Makuch took apart the engine in his roadster to begin trying to figure out how to make it go even faster.